1. Field of the Invention
The present invention relates to an infant security system for use in hospitals to prevent kidnappings and mixups of newborn infants.
2. Description of Prior Art
In recent years, there have been numerous well publicized infant kidnappings in hospital maternity wards. Even more prevalent are those cases where infants have been inadvertently switched at birth or shortly thereafter with another infant. In the case of kidnappings, the results have often been tragic with the newborn infant never being found. In the case of mixups, parents have left the hospital with the wrong infant only to find out months or even years later about the mistake.
Hospitals have responded to the problem by increasing their levels of security and by adding additional staff members . Restricted access to maternity wards is also commonplace as a means of increasing security. These measures have proven to be largely ineffective in preventing either kidnappings or mixups. In the case of kidnappings, the perpetrator is often knowledgeable of hospital procedures and language and passes themselves off as a staff member. The infant is then removed from the maternity ward without raising the suspicion of the hospital staff.
In the event of a mixup, there is little likelihood of discovery since the only identification system in use by most hospitals is a plastic band placed upon the infant's wrist. There is no prior art automated system or device known to the author which can uniquely match newborn infants to their rightful mothers by providing a pair of matching security tags having encoded transmission signals which must match one another, and; which can simultaneously monitor the continued presence of infants.
A requirement thus exists for a security system which can prevent infant kidnappings and mixups in hospital maternity wards. In order to fully appreciate the novel features of the present invention, it is first necessary to delineate at least some requirements which a typical hospital would have for an infant security system. First and foremost, the system must have the ability to solve the two problems which have produced the need for such a system. That is, the system must be able to continually monitor the presence of infants within the hospital and must simultaneously provide a means of uniquely identifying each infant. In order to useable in the hospital environment, the system must allow for free movement of infants without compromising their security. Additionally, the system must provide for various medical tests to be conducted which may require that the infant be wearing no metallic objects. The system must be highly resistant to tampering since kidnappers are often aware of hospital procedures and speech mannerisms. Finally, the system must immediately notify hospital staff in the event of an infant mixup or kidnapping attempt. Heretofore, only limited prior art has existed specifically for infant security systems although other types of security systems may be of limited use. U.S. Pat. No. 4,899,134 to Wheeless (1990) describes a magnetic strip which is imbedded in an umbilical cord clamp attached to the infant. The clamp thus becomes a passive tracking device which can be detected by receiving apparatus at exits to the hospital. However, if discovered by a person attempting to kidnap the infant, the Wheeless device can be removed, rendering it ineffective. It is even likely that an untrained person could seriously injure an infant while attempting to remove an umbilical cord clamp. The claim by Wheeless that an advantage is gained by making the device unobtrusive does not consider the deterrent effect of security devices which are plainly visible. Wheeless undermines his original premise of providing an undetectable security device by disclosing an embodiment comprised of a battery powered radio transmitter which could be attached to the end of the umbilical cord clamp. Given the present state of technology in the area of miniaturization, it is unlikely that such a device could be reduced to practice in such small size as to be capable of being imbedded within the umbilical cord clamp of a newborn infant. Finally, the Wheeless device fails to disclose a means to uniquely identify infants in order to prevent mixups in hospitals.
U.S. Pat. No. 4,853,692 to Wolk et. al. (1989) discloses a second security system which is designed for infants which employs a radio frequency transmitter enclosed in a rugged plastic housing and attached with a plastic strap having a single conductor imbedded within. No means is disclosed for removing the plastic strap although a switch inside the plastic enclosure can be accessed to deactivate the tamper protection afforded by the strap. No protection is offered if the strap is partially severed or stretched. Since the device is described several times as being housed in a rugged plastic enclosure, no thought has been given to the comfort of the infant or to making the device easy to remove. A receiver placed on the infant's cart detects removal of the infant and tag from the immediate vicinity thus limiting tha ability of staff to move the infant freely within the hospital. A secondary protection is afforded by the inclusion of a magnetized strip affixed to the transmitter module which is used in conjunction with another group of receiving devices located at exits to the hospital. As previously stated, this strip can be removed thus rendering this type of protection ineffective. Finally, no disclosure is made as to any ability of the system to prevent mixups of infants.
U.S. Pat. No. 5,014,040 to Weaver et al. (1991) teaches a personal locator transmitter for use in a nursing home environment wherein there is a radio frequency transmitter enclosed in a plastic case similar to that of a large wristwatch and which includes a plastic strap with imbedded conductor to detect tamper attempts. The strap contains a ratcheting mechanism which requires that the strap be severed to remove the transmitter. This method of attachment is adjustable in only one direction and requires a special key to be inserted for periodic removal if necessary. As with other prior art, the strap can be stretched somewhat without breaking the security element thus defeating the tamper protection mechanism. Weaver discloses a means of changing the power output of the transmitter, but such change is made by a variation in the manufacturing process and cannot take place automatically within the tag. Furthermore, no means is provided for deactivating the tag once the case is closed.
U.S. Pat. No. 4,851,815 to Enkelmann (1989) depicts a security device which contains an encoded RF transmitter used in conjunction with an electrically conductive security element to monitor objects or persons. The Enkelmann device emits an audible alarm when removed from a continuous RF field , or alternatively; emits the same alarm in the presence of a different RF field. In the event the security element is severed, the alarm is also made to sound. The security element consists of a coaxial cable whereby the inner conductor forms a complete circuit and the outer sheath or conductor forms the transmitter aerial. The aerial in Enkelmann is part of a tuned circuit which would be compromised in the event the length of the security element needed to be changed to accommodate people or objects of different size. There is no means disclosed by Enkelmann for removal or reattachment of the device. The device could also be defeated by stretching the security element in the process of removal. A group of internal switches must be set to produce the digital code thus causing the device to be unnecessarily large.
U.S. Pat. No. 4,952,913 to Pauley (1990) also teaches a device employing an RF transmitter used in conjunction with a conductive band to affix an active tag to personnel being monitored. Pauley further teaches the use of capacitive coupling techniques to insure that the band is in place about the wrist or ankle of a human being. An AC signal is imposed upon a conductor which is arranged in parallel with a second conductor. The signal from the first conductor is coupled by the proximity of human skin to the second conductor. The presence of this signal is then continuously monitored. The Pauley device must be fastened tightly enough to maintain this capacitive coupling. The band of the Pauley device must be also be completely severed in order to detect its removal. If it were possible to place a finger beneath the band of the Pauley and stretch it over the ankle or wrist, the capacitive coupling would remain in effect, the band would not have been severed and the system would have been defeated. Finally, the Pauley device discloses a requirement for coding switches to set the coded identity data transmitted by the tag; a coding method which is also present in other prior art.
U.S. Pat. No. 4,682,155 to Shirley (1987) discloses a security system for monitoring persons within a nursing home environment whereby the resident wears an electronic trigger module to sound an alarm when a door equipped with a receiver module is opened. The transmission range of the Shirley deice is purposely limited to a few feet thus making it unsuitable for continuous monitoring of a person or object which might be located some distance from the door. Furthermore, the Shirley device is attached with a strong, non removable band making it easy to defeat if the band is severed and the person or object is removed leaving the trigger device behind.
It is thus well known that an electronic method may be employed to monitor persons or objects using either active or passive security tags affixed by a band to the subject being monitored. It is also well known that such bands may contain a conductive security element which, if severed, will create an alarm condition. The present invention however overcomes limitations of all known prior art by providing an infant security system having a security tag which is easily removable yet which can detect the band being severed, stretched or removed; the band in acuality being a security element attachment apparatus. The present invention provides a security tag which is easily removable and is therefore contrary to the teachings of prior art. The problem of providing a removable security tag is unrecognized in prior art which typically employs the strongest types of non removable bands. Furthermore, the present invention employs a security element which can detect being stretched as well as being severed which is a feature not suggested by prior art. In addition, the present invention omits the element of coding switches in known prior art while maintaining the capability of transmitting a coded identity signal. Finally, the present invention solves the problem of providing a method of deactivating expendable security tags after use which is unrecognized in prior art disclosures.
At first glance, several prior art devices would appear to be useful in providing security to newborn infants; however they each suffer from major deficiencies. Prior art devices contain no provision for periodic removal if necessary or for deactivating if required for testing within the hospital environment. Capacitive coupling to human skin as a method of detecting removal may not be possible under all circumstances. For example, infants who lose weight shortly after birth would cause the Pauley device to become loose and erroneously cause an alarm. The Pauley device is also limited to use on a human being by teaching capacitive coupling as a means for determining the continuing proximity to human skin and is thus not suitable for protecting objects in addition to persons.
Prior art devices which may be adaptable for infant security do not consider those requirements which are unique to the hospital environment. Rather, the band which is used to attach virtually all such devices is usually made as difficult as possible to remove. No existing device known to the inventor currently can accommodate the changing size of an infant's arm or leg as a result of weight loss. No security device disclosed in prior art contains a security element which is easily removed yet which can detect being severed as well as being stretched. Known prior art devices can be defeated by removal or stretching the attachment band in such a way that the conductive security element is not broken. While there are known conductive security elements which cannot be stretched, these are specified to be comprised of such materials as steel cable as in the case of U.S. Pat. No. 4,962,369 to Close (1990), or mechanical jaws such as disclosed in U.S. Pat. No. 4,573,042 to Boyd (1986). No known prior art security system is comprised of a tag which lends itself to attachment on the ankle or wrist of a newborn infant. Furthermore, none of the known existing technologies lend themselves to easy removal or adjustment of the attachment band nor do they provide a means for continuously monitoring both the unique identity and location of a person or article.
The present invention thus meets a long felt but previously unsolved need for a removable and adjustable security tag which can prevent infant kidnappings and mixups while overcoming the deficiencies of prior art as will be clearly seen from disclosure of the claims herein.